In 2013, before Austin Clark's redshirt senior season at Cal started, the defensive lineman tore his ACL.

The former walk-on called home to his mother, Charlotte, while the doctor called Clark's father, Alan.

The family's overriding thought?

"This is it," Alan Clark said. "It's over for him. He'd never play again."

But Austin gathered all of his medical records, filled out the paperwork, and wrote his plea to the NCAA for a sixth year of eligibility. The clearance call came in January, and Clark shed a few tears before telling his parents and teammates that he was coming back for one more season.

"When you turn that film on, and you see him running around," Cal defensive coordinator Art Kaufman said, "It's not important to him (to be out there). It's critical to him."

For Clark to even come to Cal was a risk. He was a walk-on in 2009, and his parents paid tuition for Austin's first three years before he landed a football scholarship in 2012.

Not long after, Clark planted his foot and a shot of pain pumped through his body. He tried to finish the practice, but the bruising and swelling on his foot told the Bears' trainers there was a problem.

"They knew it as soon as they looked at it," Clark said. "That was right before what I thought was going to be a big year."

He missed all of fall camp and the first game before playing in the second with steel in his shoes. He missed the next game and tried to play against USC. After one play, Clark knew he was done. The 2012 season was a loss.

Last year, he returned healthy for what would have been his redshirt senior year. But while doing extra work in the south corner of the end zone, Clark twisted the wrong way. Teammate Brennan Scarlett saw him hold his knee and say that something was wrong. With both injuries, Clark stayed on his feet rather than falling to the ground.

"Austin doesn't ever drop," Scarlett said.

Now, after five chaotic years at Cal, Clark has one last chance to make an impact.

For the 24-year-old, being the elder statesman - with two plates and four screws in his foot - is a motivator.